Updated at 3:46 p.m. ET

Sen. Al Franken, D-Minn., facing multiple allegations of sexual misconduct, announced Thursday that he will be resigning. Speaking on the Senate floor, Franken said serving in the Senate has been "the great honor of my life" and that nothing he has done as a senator "has brought dishonor" on the institution. But he said, "it's become clear that I can't both pursue the Ethics Committee process and at the same time remain an effective senator" for the people of Minnesota.

The committee had begun a preliminary investigation into charges from several women that Franken tried to kiss them or inappropriately touch them. Some of the alleged incidents did take place while Franken was in office.

In his remarks, Franken noted what he called "the irony" — that he is stepping down, "while a man who has bragged on tape about his history of sexual assaults sits in the Oval Office, and a man who has repeatedly preyed on young girls campaigns for the Senate with the full support of his party." Franken was referring to President Trump, who has faced accusations of sexual misconduct that he denies, and Alabama Senate candidate Roy Moore, a Republican.

"I am proud that during my time in the Senate I have used my power to be a champion of women and that I have earned a reputation as someone that respects the women I work alongside every day," he said on the Senate floor. "I know there has been a very different picture of me painted in the last few weeks, but I know who I really am."

He said he would be resigning "in the coming weeks."

On Wednesday, about two-thirds of the Democrats in the Senate — including almost all of the women in the Senate Democratic Caucus — called for Franken to step down. Among those urging him to resign were the top three Democrats in the chamber — Minority Leader Chuck Schumer of New York, Sen. Dick Durbin of Illinois and Sen. Patty Murray of Washington. In addition, Tom Perez, chairman of the Democratic National Committee, also called for Franken to step down.

Franken was again accused of sexual misconduct as recently as Wednesday. A woman told Politico that Franken tried to kiss her after she appeared on his radio show in 2006 prior to his election to the Senate. The woman, who was not named in the article, said Franken claimed, "It's my right as an entertainer." Franken denied the allegation. "This allegation is categorically not true and the idea that I would claim this as my right as an entertainer is preposterous. I look forward to fully cooperating with the ongoing ethics committee investigation," Franken said in a statement, according to Politico.

In The Atlantic, writer Tina Dupuy said she was groped by Franken in early 2009. It was not clear from the Atlantic report whether the publication had reached out to Franken for comment and, if so, how Franken had responded.

Calling for Franken's resignation was clearly a difficult decision for some Senate Democrats. Many cited their friendships with the former Saturday Night Live comedian and writer. He has done fundraisers for some of them, and he has held positions on issues, including abortion rights, that are in line with the views of most Democratic female officeholders.

Franken was first elected to the Senate in 2008. After leaving SNL, he authored several books, among them Rush Limbaugh Is a Big Fat Idiot. Franken then became a radio talk show host himself in 2004 on the liberal Air America network. In 2008, he challenged Republican incumbent Sen. Norm Coleman in Minnesota. The race was exceedingly close; after several counts, it was determined Franken won by 312 votes, a margin finally upheld by Minnesota's state Supreme Court.

Franken wasn't sworn in until July 7, 2009.

Once seated, Democrats had 60 votes in the Senate, and they were able to overcome Republican opposition and pass the Affordable Care Act, also known as "Obamacare," in Congress' upper chamber. Franken took a predictably liberal position on issues, winning a 100 percent liberal rating from The Almanac of American Politics. He also adopted a new tone, eschewing the jokes of his previous career for a more serious demeanor.

He had a much easier time winning re-election in 2014, capturing 53 percent of the vote.

This year, Franken played a key role in the questioning of President Trump's Cabinet choices, including on the Senate Judiciary Committee where he grilled then-Attorney General nominee Jeff Sessions on his contacts with Russia. Sessions, who had been a top Trump campaign surrogate, told Franken he didn't recall any communications with Russians. But after reports surfaced that Sessions did indeed meet with the Russian ambassador to the U.S., Sessions was forced to recuse himself from the Department of Justice investigation into Russian interference with the 2016 presidential election and possible ties between Russia and the Trump campaign.

Franken had been talked about as a potential Democratic presidential candidate in 2020. There was even a "Draft Al Franken" website. During an interview to promote his most recent book, Al Franken, Giant of the Senate, he told NPR's Scott Detrow he wasn't interested in the Oval Office, and in a comment that has special resonance amid the current controversy, he said he was "very happy being a United States senator representing the people of Minnesota."

Back home, the news of his resignation hit supporters hard. Democrat Emily Gilmore watched Franken's speech at a food court in downtown Minneapolis.
She says Franken did what he had to do.

"I think he did things he's probably not proud of and I don't think we want someone representing us who has those allegations against him," she said. "And quite frankly, he probably wouldn't be resigning if there wasn't truth in them."

At the student union on the University of Minnesota's Duluth campus, it was quiet as the senator spoke. Bella Maki, vice president of the college Democrats, said she had hoped Franken would run for president one day.

"I was heartbroken. I shed a couple tears. And it's really unfortunate because I agreed on his politics and the agenda he tried to push and often times succeeded, so I'm very saddened," she said.

It will be up to Minnesota Gov. Mark Dayton, a Democrat, to pick a successor to Franken. The successor will take office until a November 2018 special election determines who would serve out the last two years of Franken's term.

The slew of recent calls for Franken to step down came a day after Rep. John Conyers, D-Mich., announced his resignation Tuesday after more than 50 years in the House of Representatives. The end of Conyers' half-century tenure in office was the result of days of pressure after multiple allegations of sexual harassment were leveled against him. After Conyers resigned, Politico reported that members of the Congressional Black Caucus, which Conyers had helped to found, saw a double standard in how the longtime African-American lawmaker had been treated and how other white politicians — including Franken — were being treated over similar claims of sexual misconduct.

Another House Democrat, Rep. Ruben Kihuen of Nevada, is also under pressure to resign after a former campaign staffer alleged he had sexually harassed her.

Copyright 2017 NPR. To see more, visit http://www.npr.org/.